diff --git a/devlog/2026-09-11_qualitygate-algo-config-keys/REQ.md b/devlog/2026-09-11_qualitygate-algo-config-keys/REQ.md
new file mode 100644
index 00000000..a703b790
--- /dev/null
+++ b/devlog/2026-09-11_qualitygate-algo-config-keys/REQ.md
@@ -0,0 +1,40 @@
+# REQ — qualityGate.algorithms nested params falsely flagged as "Unknown keys" (#329)
+
+## Problem
+
+Configuring per-algorithm quality-gate parameters triggers a false startup warning:
+
+```jsonc
+{
+  "qualityGate": {
+    "enabled": true,
+    "algorithm": "rouge-recall-v1",
+    "algorithms": {
+      "rouge-recall-v1": {
+        "layer1MinChars": 200,
+        "layer1MinRetentionPct": 2.5,
+        "layer2MaxRougeF1": 0.05,
+        "layer2MaxTop20Recall": 0.20
+      }
+    }
+  }
+}
+```
+
+`ACP: config warning — Unknown keys: qualityGate.algorithms.rouge-recall-v1...`
+
+The config is legal and consumed at runtime (`lib/compress/quality-gate/evaluate.ts:104` reads `qg.algorithms[algoName]`) — only the key-allowlist check is wrong.
+
+## Root cause
+
+`getConfigKeyPaths()` in `lib/config-validation.ts` recurses into `qualityGate.algorithms` because it isn't in the dynamic-key skip list (unlike `compress.providers`, `messageFilters.filters`, `compress.modelMaxLimits`). Every nested key it emits (`qualityGate.algorithms.rouge-recall-v1`, `...layer1MinChars`) fails the static allow-list lookup.
+
+## Fix
+
+Add `qualityGate.algorithms` to the recursion skip list with a comment explaining the dynamic-map convention (next path segment = user-chosen algorithm id; inner shape validated by the owning subsystem).
+
+## Acceptance
+
+- [x] New tests: nested algorithm keys → no warning; sibling unknown keys still flagged
+- [x] Full suite + typecheck green
+- [ ] Dual-agent review
diff --git a/devlog/2026-09-11_qualitygate-algo-config-keys/WORKLOG.md b/devlog/2026-09-11_qualitygate-algo-config-keys/WORKLOG.md
new file mode 100644
index 00000000..3614b495
--- /dev/null
+++ b/devlog/2026-09-11_qualitygate-algo-config-keys/WORKLOG.md
@@ -0,0 +1,10 @@
+# WORKLOG — qualityGate.algorithms config-key fix
+
+1. Reproduced from issue #329 config sample: `getInvalidConfigKeys` returned `qualityGate.algorithms.rouge-recall-v1.*` paths.
+2. Located skip-list in `lib/config-validation.ts::getConfigKeyPaths`, added `qualityGate.algorithms` (+ explanatory comment).
+3. Added 2 tests in `tests/config-validation.test.ts`:
+   - nested algorithm params → `[]` (no warning)
+   - unknown sibling key (`qualityGate.notARealKey`) still flagged while algorithm params pass
+4. Verification: config-validation suite 47/47; full suite 1209/1209; typecheck clean.
+5. Dual-agent review dispatched on the PR.
+6. Review follow-up (issue #329 floor, ranxianglei): the example/test param names used non-existent keys `minSummaryLength` / `rougeF1Threshold`. Corrected to the real `rouge-recall-v1` params (`layer1MinChars`, `layer1MinRetentionPct`, `layer2MaxRougeF1`, `layer2MaxTop20Recall`) in `REQ.md` (config sample + root-cause prose) and both new tests. Unknown inner keys are silently ignored at runtime, so the old sample would have configured params that never take effect. No logic change — validation fix untouched; suite re-verified green.
diff --git a/lib/config-validation.ts b/lib/config-validation.ts
index 3d56f41f..dba379fa 100644
--- a/lib/config-validation.ts
+++ b/lib/config-validation.ts
@@ -84,8 +84,14 @@ function getConfigKeyPaths(obj: Record<string, any>, prefix = ""): string[] {
             fullKey === "compress.modelMaxLimits" ||
             fullKey === "compress.modelMinLimits" ||
             fullKey === "compress.providers" ||
-            fullKey === "messageFilters.filters"
+            fullKey === "messageFilters.filters" ||
+            fullKey === "qualityGate.algorithms"
         ) {
+            // Dynamic-key maps: the next path segment is a user-chosen name
+            // (provider id, filter id, registered algorithm id) whose inner
+            // shape is validated by the owning subsystem, not by this static
+            // allow-list. Recursing would flag every legal entry as
+            // "Unknown keys" (#329).
             continue
         }
 
diff --git a/tests/config-validation.test.ts b/tests/config-validation.test.ts
index fcb93578..8a9e3e51 100644
--- a/tests/config-validation.test.ts
+++ b/tests/config-validation.test.ts
@@ -55,6 +55,29 @@ test("getInvalidConfigKeys does not recurse into messageFilters.filters dynamic
     assert.deepEqual(result, [])
 })
 
+test("getInvalidConfigKeys does not recurse into qualityGate.algorithms dynamic keys (#329)", () => {
+    const result = getInvalidConfigKeys({
+        qualityGate: {
+            enabled: true,
+            algorithm: "rouge-recall-v1",
+            algorithms: {
+                "rouge-recall-v1": { layer1MinChars: 200, layer2MaxRougeF1: 0.3 },
+            },
+        },
+    })
+    assert.deepEqual(result, [])
+})
+
+test("getInvalidConfigKeys still flags unknown qualityGate keys while allowing algorithm params (#329)", () => {
+    const result = getInvalidConfigKeys({
+        qualityGate: {
+            algorithms: { "rouge-recall-v1": { layer1MinChars: 200 } },
+            notARealKey: true,
+        },
+    })
+    assert.deepEqual(result, ["qualityGate.notARealKey"])
+})
+
 test("validateConfigTypes returns empty array for valid config", () => {
     const result = validateConfigTypes({
         enabled: true,